Minutes of Meeting Held at the White House on Monday 18 June 1945, at 1530.
Document 598 of Foreign Relations of the United States (FRUS).

Diplomatic Papers: The Conference of Berlin (Potsdam Conference), 1945. Vol. I (Washington, DC, GPO 1960, pp. 902-911). General Marshall read into the record the summary offered by General Hull (document 7 above). Tables from JCS 1388 were used at the meeting. Because some disagreement persisted over the specific language of
JCS 1388, the document itself was not given to the President at that time. In fact, the agreed version was
not completed until 11 July, when it was included in the background papers for the Potsdam Conference.

Admiral Leahy said that the rate of casualties in Okinawa would probably be equaled in an invasion of Kyushu, and that was a 34% rate of casualties. Admiral King thought that the number would be lower since there was a lot more room to maneuver on Kyushu then there had been on Okinawa. What was not discussed, apparently, was the intensity of the kamikaze attacks that would happen. It's likely that it would have been the worst wave of kamikaze attacks of the entire war.

In order to get control over Honshu, airfields on Kyushu would be needed. FDR apparently felt that the Kyushu invasion alternative was acceptable.

Admiral Leahy thought that our insistence on unconditional surrender was not good, and that it might make the Japanese fight harder and increase U.S. casualties. The section also seems to say that FDR was leaving room for Congress to make some kind of move not requiring unconditional surrender, but, for the moment, he was sticking with unconditional surrender to satisfy public opinion.

One of the rare instances where I have found something stated about the race factor.